aura: Try to make Linux host resize code more reliable.

ui/aura/desktop.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_AURA_DESKTOP_H_
 #define UI_AURA_DESKTOP_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
@@ skipping 51 matching lines @@
   Window* active_window() { return active_window_; }
   Window* mouse_pressed_handler() { return mouse_pressed_handler_; }
   Window* capture_window() { return capture_window_; }
   ScreenAura* screen() { return screen_; }
 
   void SetDelegate(DesktopDelegate* delegate);
 
   // Shows the desktop host.
   void ShowDesktop();
 
-  // Sets the size of the desktop.
+  // Sets the size of the desktop.  Note that in some implementations (i.e.
+  // X11), resizing happens asynchronously, so a size passed to SetHostSize()
+  // may not be immediately reflected in GetHostSize().

[sadrul, 2011/10/22 18:53:04]

I dislike this part of the change.

I confirmed that, with at least ion3, a Desktop->SetHostSize triggers a
ConfigureNotify event, even though it ignores the resize request. I think we
should either keep the current behaviour (this would be my preference), or wait
for ConfigureNotify before returning from SetSize.

[Daniel Erat, 2011/10/23 04:02:55]

I'm in favor of waiting for the ConfigureNotify before returning (since keeping
the current behavior means that we're confused about our size for a period of
time).  ICCCM requires that WMs send a synthetic ConfigureNotify even if they
ignore the request IIRC; I just wasn't sure if that was another part of the spec
that Tuomo disagreed with. :-P

   void SetHostSize(const gfx::Size& size);
   gfx::Size GetHostSize() const;
 
   // Shows the specified cursor.
   void SetCursor(gfx::NativeCursor cursor);
 
   // Shows the desktop host and runs an event loop for it.
   void Run();
 
   // Draws the necessary set of windows.
@@ skipping 111 matching lines @@
   Window* mouse_moved_handler_;
   Window* focused_window_;
   Window* touch_event_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(Desktop);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_DESKTOP_H_